UC-NRLF 


261 


Isogeotkerm  Hypothesis 

^"MINERAL  OCCURRENCE  and  ORIGIN 

Ike  ORIGIN  of  PETROLEUM 

Coal,  and  Otter  Carbonaceous  Products,      By  Wm.  Plotts 


GIFT   OF 


^ 


Isogeotnerm  Hypothesis 

o/"Mineral  Occurrence  and  Origin 

Origin  V  Petroleum 

Coal,  and  Other  Carbonaceous  Products. 


Snowing  how  these  products  occur  in  orderly,  definite, 

limited  horizons,  independently  of  the 

plane  of  stratification. 


By  WM.   PLOTTS 

i#ier,  California. 


Whittier,  Calif ornia.    April,  1911. 
Price,  $1.00. 


WILL  A.  SMITH'S  PRINT  SHOP 

Whiter.    California 
191  1 


ISOGEOTHERM  HYPOTHESIS 


OCCURRENCE*/ COAL,  PETROLEUM,  &c 

^Petroleum  and  coal  occur  in  strata  of  various 
ag'es,  the  general  series  of  which  may  be  of  the 
greatest  variety  of  texture  and  hardness,  and  the 
general  appearance  of  which  may  vary  greatly 
in  different  fields,  but  in  every  region  where  they 
occur  there  is  a  something  in  common  that  is  more 
or  less  discernahle  to  the  observer,  but  which  is 
very  difficult  to  describe.  I  am  not  now  referring 
to  the  oil  stains  or  coal  blossom  that  are  generally 
easily  distinguishable  where  erosion  has  cut  into 
or  through  the  oil  or  coal  horizons,  but  to  the 
series  of  strata  in  general,  extending  thousands  of 
feet  above  and  below  those  products. 
d^Many  observers,  in  trying  to  define  this  simi- 
larity, call  it  the  age  of  the  strata,  it  apparently 
being  much  younger  and  more  crumbly  than 
strata  in  the  same  series  many  thousands  of  feet 
under  it,  but  this  is  not  the  true  solution,  as  dif- 
ferent oil  and  coal  bearing  strata  vary  greatly  in 
age,  as  determined  by  the  fossils  occurring  m 
them;  those  of  Pennsylvania,  for  instance,  being 
probably  several  times  as  old  as  those  of  Califor- 
nia. The  true  solution  is:  each  horizon  of  like 
products  has  been  subjected  to  a  like  approxi- 


ISOGEOTHERM  HYPOTHESIS 


mate  pressure  from  the  mass  of  material  above  it, 
and  to  an  exactly  lite  maximum  of  heat  at  the 
time  of  its  greatest  subsidence;  and  that  this  heat 
was  the  point  of  distillation  of  these  products 
(probably  several  hundred  degrees),  seems  quite 
plain,  and  that  the  source  of  this  heat  was  the 
presence  of  enough  material  above  the  carbona- 
ceous horizons  to  create  it  through  the  orderly 
increase  of  heat  downward  in  the  earth  s  crust, 
must  become  apparent  as  soon  as  the  facts  in  con- 
nection are  generally  known. 

^  The  classification  of  strata,  according  to  the 
amount  of  pressure  and  heat  they  were  subjected 
to,  is  of  the  greatest  importance  from  a  mineral 
standpoint,  when  we  consider  that  most  of  the 
earth's  present  land  surface  has  plainly  had  miles 
of  material  eroded  from  above  it.  This  feature 
must  not  be  lost  sight  of  if  we  expect  to  form 
rational  theories  of  the  present  condition  of  any 
part  of  this  grand  old  earth  s  sub-surface. 
^L  The  original  superficial  deposits  above  the 
petroleum  must  have  been  so  vast,  that  where 
only  half  of  them  remain,  the  petroleum  must  be 
hopelessly  beyond  our  reach.  That  this  is  so,  is 
proven  in  many  ways,  the  most  simple  of  which 


ISOGEOTHERM   -IYPOT  IESIS 


is  the  very  slow  augmentation  of,  or  increase  of 
firmness  m  the  strata  as  you  trace  them  strata- 
graphically  downward.  It  also  seems  plain  that 
thousands  of  feet  of  the  upper  portion  of  the 
original  deposits  could  have  been  little  else  than 
loose,  incoherent  masses,  owing  to  the  lack  of 
sufficient  pressure  and  heat  to  knit  them  into 
substantial  strata,  sufficiently  firm  to  resist  the 
wave  erosion,  as  they  emerged  above  the  surface 
of  the  ocean. 

41,  In  the  following  pages  I  intend  to  show  that 
petroleum,  in  the  continuance  of  its  aggregate 
occurrence,  forms  a  definite,  limited  horizon 
independently  of  the  plane  of  stratification;  and 
I  hope  that  the  reader  will  not  lose  sight  of  the 
grand  and  enormous  scale  on  which  the  series  of 
deposits  were  originally  laid  down,  the  slow  rate 
of  increase  of  heat  in  nearly  all  strata,  and  not 
to  expect  to  observe  a  "made  to  order  ,  or  con- 
tinuously regular  horizon,  because  nature  has  been 
the  constructor,  and  she  does  not  work  along 
geometrical  lines;  and  I  hope  to  convince  you  that 
it  occurs  in  a  former  isogeotherm  (plane  of  equal 
heat  in  the  earth) ,  and  that  coal,  and  many  other 
more  or  less  closely  related  products,  occur  in  like 


ISOGEOTHERM  HYPOTHESIS 


manner,  also  limestones  of  like  type,  and  ttat 
many,  perhaps  most  of  our  mineral,  and  non-min- 
eral eartt  products  nave  a  closer  relationship  to 
each  otter,  ttan  tas  teen  supposed.  Most,  if  not 
all,  of  tte  metallic  minerals  seem  to  occur  in  tori- 
zons  independently  of  tte  stratification,  that 
represent  former  isogeotterms;  tut  ttey  do  not 
necessarily  occur  in  tteir  zones  of  former  fusion 
or  volatilization;  for  instance,  certain  cartonate 
iron  ores  of  a  certain  type  occur  numerously  in, 
and  seem  to  te  confined  to,  tte  coal  tonzons. 
Ttey  may  te  said  to  te  of  purely  ctemical  origin, 
tut  it  seems  ttat  ttey  required  a  certain  degree 
of  teat  in  order  to  enatle  tteir  constituents  to 
comtine. 

^L  In  pointing  out  tte  origin  of  petroleum,  and 
otter  carbonaceous  products,  I  am  not  going  to 
tring  to  my  aid  any  tteoretical  conditions  of  an 
exceptional  or  miraculous  nature,  or  conditions 
ttat  migtt  result  from  some  catastropte;  tut  am 
merely  pointing  out  wtat  must  occur  under  nor- 
mal conditions,  suet'  as  we  know  of  today. 
CL  To  give  a  tetter  understanding  of  tte  sutject, 
I  will  now  give  in  tnef  a  summary  of  my  con- 
ception of  tow  petroleum  and  kindred  products 


ISOGEOTHERM  HYPOTHESIS 


were  concentrated  in  strata,  and  the  probable 
source  of  the  carbonaceous  matter  from  which 
they  were  formed. 

^  All  authorities  of  any  note  now  concede  that 
most  parts  of  the  dry  earth  show  evidences  of 
former  subsidence  and  emergence  during  incon- 
ceivably long  ages  of  time,  and  may,  and  some 
certainly  have,  repeated  the  process  over  and  over 
again,  and  that  some  of  these  subsidences,  and 
subsequent  elevations,  have  amounted  to  several 
miles  vertically.  Of  course  this  may  seem  fan- 
tastic to  many,  but  I  am  only  appealing  to  those 
who  have  given  the  matter  some  thought  and  in- 
quiry. The  best  evidence  that  we  can  get  is, 
that  this  buckling  of  the  earth's  strata  is  going 
on  now  as  actively  as  ever,  and  has  been  going  on 
for  a  time  that  is  practically  infinite, 
d^  AiVe  see  different  kinds  of  debris  and  sedi- 
ment carried  continually  into  oceans,  building 
up  the  strata  on  the  bottom.  In  this  sediment  is 
a  proportion  of  vegetable  matter,  composed  mainly 
of  finely  ground  up  leaves,  etc.  The  remains  of 
the  lowest  animal  life  might  also  in  some  cases, 
be  sufficiently  preserved  to  contribute,  but  the 
vegetable  remains  would  seem  to  be  ample. 


ISOGEOTHERM  HYPOTHESIS 


CL  Of  course,  the  percentage  of  suck  remains  in 
any  strata  might  be  small,  but  the  aggregate  in 
miles  vertical  of  strata  would  be  enormous,  and 
from  such  deposits  perhaps  miles  thick,  we  might 
expect  to  come  the  principal  part  of  the  carbon- 
aceous matter  that  forms  our  petroleum,  coal,  our 
massive  limestones,  and  allied  minerals. 
^L  Now,  we  know  that  downward  in  the  earth  s 
crust,  the  heat  increases.  To  the  thoughtless  this 
increase  of  heat  might  seem  too  slow  to  be  applic- 
able to  our  purposes, but  we  recollect  that  nature  s 
operations  are  conducted  on  a  grand  and  tremen- 
dous scale. 

4I,Of  course,  where  a  succession  of  regular  strata 
is  being  built  on  an  ocean  floor,  there  is  a  gradual 
subsidence  of  the  region,  which  might  continue 
many  million  years,  and  after  the  subsiding  strata 
became  sufficiently  hot,  on  account  of  the  con- 
stantly added  material  above  it,  the  heat  would 
drive  the  distilled  matter  from  the  leaves,  wood, 
etc.,  upward.  Or  rather,  the  resulting  volatil- 
ized matter,  instead  of  subsiding  with  the  strata, 
would  maintain  its  relative  distance  from  the 
surface,  or  at  least  from  the  bottom  of  the  ocean, 
as  the  constantly  reinforced  mass  subsided,  "skim- 
eight 


ISOGEOTHERM  HYPOTHESIS 


mecT  of  its  carbonaceous  matter,  which  accumu- 
lated in  quantity  according  to  the  amount  of 
subsidence,  and  the  richness  in  said  matter. 
d,To  those  who  nave  had  experience  in  confin- 
ing gases  under  great  pressures,  there  is  no  dif- 
ficulty in  conceiving  the  possibility  of  compounds 
of  carbon  penetrating  and  permeating  any  strata 
when  at  several  hundred  degrees  temperature 
and  tons  pressure  per  square  inch,  and  at  the  time 
of  maximum  subsidence  of  the  region,  which 
would  only  occur  after  ages,  the  varying  car- 
bon compounds  would  be  left  blended  with  the 
strata,  confined  to  a  definite,  vertically  limited, 
horizon,  which  would  occur  independently  of 
the  plane  of  stratification,  and  during  the  long 
ages  of  emergence  and  erosion,  they  would  become 
further  concentrated,  and  more  or  less  firmly 
fixed  by  chemical  affinity  in  the  different  forms 
in  which  they  are  now  found. 

HOW  PETROLEUM  OCCURS  in  STRATA 

C[,  Petroleum  occurs  in  any  kind  of  porous  strata 
that  happened  to  be  in  its  horizon  of  general  oc- 
currence. This  horizon  is  always  limited  verti- 
cally, and  in  its  continuance  thruout  large  areas 


ISOGEOTHERM  HYPOTHESIS 


always  occurs  independently  of  the  plane  of 
stratification.  Of  course  I  do  not  mean  that  the 
horizon  is  evenly  or  continuously  productive  in 
petroleum;  hut  that  the  successive  or  overlapping 
deposits  all  occur  in  this  limited  horizon;  often 
with  very  extensive  unproductive  gaps  between 
the  productive  portions.  The  common  practice 
of  speaking  of  successive  horizons,  one  or  more 
ahove  others,  is  incorrect  and  misleading,  as  there 
cannot  strictly  he  more  than  one  oil  horizon  in 
the  same  locality. 

d,  ^Ve  almost  mvariahly  find  oil  in  such  envi- 
ronments as  show  that  it  could  not  possihly  have 
arrived  there  in  its  present  liquid  condition. 
Any  oil  prospector  that  has  investigated  much 
can  testify  to  this.  It  is  common  to  find  pitted 
limestones  of  the  hardest  kind  with  the  pits  full 
of  oil,  on  the  surface,  where  it  has  weathered 
for  ages,  where  the  oil  horizon  has  heen  eroded 
away. 

CL  It  1S  common  to  find  oil  in  sandstone,  and 
pehhle  rock  sometimes  of  adamantine  hardness, 
altho  much  of  the  oil  in  the  newer  formations, 
like  that  of  California, Texas,  and  Mexico, occurs 
in  sandstone  so  soft,  that  the  expanding  gas  that 


ISOGEOTHERM  HYPOTHESIS 


occurs  in  connection  with  all  oil,  pulverizes  the 
sand  strata,  so  that  sometimes  large  quantities 
issue  with  the  oil  from  the  wells,  hut  most  gen- 
erally the  stata  is  too  firm  to  cave. 
d.  Those  sandy  strata  were,  of  course,  laid 
down  under  water,  and  the  fact  that  they  are 
barren  of  water  generally,  proves  that  hefore 
the  oil  took  possession,  they  had  of  course,  sub- 
sided to  a  great  depth,  too  great  for  water 
to  occur  as  such,  the  heat  or  other  chem- 
ical action  having  disassociated  the  component 
elements. 

Cl^^V^ater  of  varying  degrees  of  impurity  some- 
times occur  in  the  oil  strata  under  the  oil,  hut  it 
seems  plain  that  where  such  is  the  case  the  presence 
of  the  water  is  the  result  of  erosion,  or  faulting, 
long  after  the  advent  of  the  oil,  and  perhaps  after 
the  surface  had  been  cut  to  within  comparative 
nearness  to  the  oil. 

d.  "Where  water  has  obtained  access  to  deposits 
of  oil  the  latter  has  generally  slowly  percolated 
to  the  surface,  or  sub-surface,  in  sufficient  quan- 
tity to  betray  the  petrolific  character  of  the 
locality  and  region.  If  the  oil  is  of  dense  kind, 
containing  much  asphalt  or  other  basic  material, 

eleven 


ISOGEOTHERM  HYPOTHESIS 


the  residuum  from  suck  seepages  sometimes  occurs 
in  large  quantities. 

4L  Of  course  the  oil  and  gas,  and  other  fluid 
substances  are  under  pressure  in  accordance  with 
their  depth,  the  discussion  as  to  the  cause  of  the 
pressure  is  without  point.  It  would  be  a  mira- 
cle if  they  were  not  under  pressure  until  tke 
pressure  is  removed  by  artificial  means. 
4L  The  actual  pressure  in  a  virgin  oil  "sand"  or 
deposit  is  always  in  accordance  with  its  depth 
below  the  surface,  and  is  probably  always  below 
the  pressure  exerted  by  a  column  of  water  from 
the  surface  to  the  deposit,  because  as  the  region 
emerges  and  the  surface  is  worn  away,  the  de- 
posit becomes  cooler,  causing  the  gases  to  condense 
and  the  pressure  to  decrease  accordingly.  Of 
course  it  often  happens  that  the  gas  pressure  in  a 
well-hole  will  overcome  the  hole-full  of  water, 
or  even  thin  mud,  causing  a  "blow  out",  but  this 
is  owing  to  gas  in  considerable  volume  having 
free  access  to  the  hole,  when  the  ascending  gas, 
by  lightening  the  column  of  water,  would  slowly 
overcome  it. 

41,  If  there   are   numerous   oil   showings   on   the 
surface  where  the  strata  is  horizontal,  or  only 

twelve 


ISOGEOTHERM  HYPOTHESIS 


moderately  tilted,  the  valuable  oil  deposits,  if  any, 
are  usually  of  only  moderate  depth  and  it  is  use- 
less to  drill  to  a  great  depth;  and  in  similar 
strata  if  oil  is  found  at  a  great  depth  there  is 
never  any  showing  on  the  surface. 
^L  Many  times  operators  have  drilled  explora- 
tion wells  a  couple  of  thousand  feet  below  the 
productive  zone  in  search  of  another  profitable 
deposit,  but  such  attempts  have  always  been  fail- 
ures. However,  in  localities  of  exceptional 
disturbance  the  oil  horizon  is  likely  to  be  more 
erratic  and  irregular  than  elsewhere. 
^L  \Ve  sometimes  read  geological  reports  of  oil 
and  gas,  where  the  writers  suggested  that  those 
products  had  moved  freely  through  the  strata 
and  had  arrived  from  afar  along  with  the  "cir- 
culating waters."  Such  writers  observation 
must  be  very  superficial  and  their  logic  faulty, 
for  those  products  are  firmly  incorporated  with 
the  strata  of  which  they  are  practically  a  part; 
were  it  not  so  they  would  have  been  lost  ages 
ago.  The  continuance  of  porosity  of  an  oil  stratum 
is  usually  quite  limited  or  the  grain  is  very  fine. 
C,  It  sometimes  happens  that  a  well  is  opened 
where  the  oil  is  under  full  pressure,  in  old  ter- 

thirtecn 


ISOGEOTHERM  HYPOTHESIS 


ritory  where  adjacent  wells  had  teen  exhausted 
and  abandoned  for  many  years,  and  many  other 
circumstances  show  us  how  thoroly  the  oil  is  con- 
fined to  the  strata  where  it  had  to  remain  ever 
since  it  was  forced  there  in  a  volatilized  form. 
C[,  There  is  a  wide-spread  notion  that  oil  is  a 
concomitant  of  certain  strata  and  that  if  it  is 
found  at  all  it  must  occur  in  those  strata,  and 
that  it  is  most  likely  to  occur  indefinitely  in  con- 
tinuation of  the  plane  of  stratification  from  where 
it  is  known  to  occur. 

4L  This  helief  has  been  a  very  costly  error,  for 
the  aggregated  deposits  of  oil  in  their  continuance, 
despite  the  irregularity  or  their  occurrence,  form 
a  definite  horizon  which  is  limited  in  vertical 
scope  and  which  is  rarely  in  exact  conformity 
with  the  bedding  over  any  considerable  scope  of 
country,  and  whenever  an  oil-containing  stratum 
extends  outside  of  the  orderly  zone  of  oil  occur- 
rence (unless  the  porosity  should  be  continuous 
beyond  any  known  example),  it  is  bound  to  be 
barren  of  oil  and  thereafter  remain  so,  unless  it 
should  re-enter  the  oil  horizon,  which  would  be 
improbable. 
4^  \Vhere  the  oil  occurs  extensively  and  per- 

fourteen 


ISOGEOTHERM  HYPOTHESIS 


sistently  in  certain  strata  to  which  it  has  teen 
narrowly  confined  over  a  considerable  area<  geol- 
ogists have  repeatedly  and  foolishly  predicted 
that  it  would  not  occur  in  adjoining  regions  or 
localities  because  they  were  stratigraphically 
much  higher  and  much  younger;  and  when  oil 
was  found  there  in  violation  of  their  warning, 
the  geologists  would  explain  that  the  original 
lower  stratum  was  the  place  of  origin  of  the  oil 
but  that  it  had  ""  migrated  upward",  and  urged 
deeper  drilling  in  order  to  tap  the  basic  sands. 
It  is  perhaps  needless  to  add  that  where  such 
advice  was  acted  on  it  was  unproductive  of  any 
good  results.  Contentions  of  this  kind  never  had 
any  basis  of  fact. 

C.  If  we  could  drill  a  well  30,000  feet  deep  do 
you  suppose  that  we  might  find  some  oil  at,  say 
1000  feet,  and  then  go  5000  feet  further  and  find 
another  batch,  and  perhaps  a  few  thousand  feet 
below  that  find  a  bed  of  coal,  etc.?  Not  at  all. 
If  oil  was  found  at  all  the  bulk  of  it  would  be 
found  to  occur  in  a  vertical  scope  of  a  few  hundred 
feet  with  possibly  traces  extending  as  much  as 
2000  feet  above,  and  a  less  distance  below,  and 
below  that  no  more  would  be  found  unless  you 

fifteen 


ISOGEOTHERM  HYPOTHESIS 


could  continue  the  hole  to  the  Hellespont  or 
China.  If  coal  occurred  it  would  be  found  above 
tne  oil,  as  it  occurs  everywhere  that  those  two 
products  are  found  in  the  same  locality. 
CL  Critics  who  fail  to  see  an  orderly,  definite 
horizon  that  occurs  independently  of  the  bedding 
in  the  apparently  irregular,  hap-hazard  group- 
ing of  the  different  oil  "fields  when  viewing 
the  matter  in  this  regard,  seem  to  be  expecting 
a  "made  to  order"  horizon  where  the  fields 
would  occur  without  wide  gaps  and  in  a  perfect 
plane;  but  nature  does  not  work  along  geomet- 
rical lines  or  in  any  manner  that  could  be  des- 
cribed as  regular,  so  I  have  described  the  hori- 
zons of  mineral  occurrence  as  " "orderly  in  the 
sense  of  their  occurrence  vertically,  because  I 
well  know  how  very  irregularly  those  products 
occur  in  their  zones  or  horizons. 
d^  Each  group  of  like  products  occurs  in  a  com- 
mon horizon,  but  any  chemist  knows  what  a  great 
difference  there  is  in  composition  of  the  dif- 
ferent kinds  of  mineral  oils,  or  of  the  different 
kinds  of  coal.  Different  kinds  of  oil  being  there- 
fore of  unlike  kind  might  be  expected  to  range  in 
different  positions  in  the  grand  horizon  of  pet- 


ISOGEOTHERM  HYPOTHESIS 


roleum  occurrence,  and  it  is  common  to  find  sev- 
eral beds  of  oil-containing  strata  overlaying  each 
other,  and  occupying  a  vertical  scope  of  possibly 
a  thousand  feet,  altho  it  is  more  commonly  con- 
fined to  three  or  four  hundred  feet.  In  Cali- 
fornia, the  several  oil  deposits  may,  including 
traces,  extend  vertically  as  muck  as  three  thous- 
and feet,  but  such  is  rare.  Much  observation  of 
the  phenomena  of  petroleum  occurrence  has  led 
me  to  think  that  cases  of  migration  of  petroleum 
out  of  its  original  zone  of  deposition  are  rare, 
except  where  erosion  has  permitted  water  to 
obtain  access  to  oil,  when  the  latter  would  slowly 
escape  to  the  surface  in  the  form  of  a  seepage, 
which  generally  would  require  thousands  of 
years  to  exhaust  a  deposit. 

4L  Petroleum  found  in  different  fields  is  never 
identical  in  composition.  It  ranges  all  the  way 
from  the  tarry  product  of  Trinidad,  Mexico, 
and  California,  to  the  light  product  of  the  Ap- 
palachian region,  Colombia,  Java,  etc.,  which  is 
nearly  as  thin  and  clear  as  water.  In  some  fields 
like  ^Vhittier,  California,  although  the  oils  may 
conform  to  a  certain  type,  there  are  hardly  two 
wells  that  produce  identical  oil.  Not  only  is  the 


ISOGEOTHERM  HYPOTHESIS 


gravity  varied,  but  the  character  of  the  oil  other- 
wise is  different.  In  the  latter  field  the  oil  hor- 
izon cuts  diagonally  across  the  trend  of  the  steeply 
upturned  strata;  and  there  are  perhaps  one  hun- 
dred different  producing  stratums;  and  as  many 
of  the  wells  obtain  oil  from  several  strata,  and 
as  each  stratum  contains  different  oil  from  its 
neighbor,  the  resultant  blend  is  rarely  exactly 
alike  in  any  two  wells.  There  is  no  such  a  thing 
as  drawing  a  definite  line  between  asphaltic  oils 
and  oils  of  paraffine  base,  as  practically  all  oils 
contain  both  asphalt  and  paraffine,  in  traces,  at 
least.  Even  in  products  resembling  either  coal 
or  petroleum,  it  is  difficult  to  draw  the  line 
between  the  two,  for  coal  and  kindred  products 
blend  into  those  resembling  petroleum. 
CL  Petroleums  of  different  character  are  often 
blended  with  shale  of  so  fine  a  grain  that  the  oil 
can  hardly  be  detected  except  by  smell.  Such 
oils  can  only  be  obtained  by  distilling  the  shale, 
which  is  done  profitably  in  some  countries.  The 
writer  has  seen  such  shales  that  looked,  to  his 
unpracticed  eye,  exactly  like  some  cannel  coals, 
which  will  also  yield  oils  by  distillation.  Lime- 
stones in  the  horizons  of  petroleum,  often  smell 

eighteen 


ISOGEOTHERM  HYPOTHESIS 


strongly  of  oil.  In  western  Texas,  and  the  lar- 
ger part  of  eastern  New  Mexico,  over  an  immense 
region,  notably  at  Las  Vegas,  the  harder  shale, 
when  freshly  Jug  smells  strongly  of  oil.  "  Stink- 
ing rock"  is  of  this  nature,  as  nearly  all  oil  pros- 
pectors know. 

CL  If  petroleum  occurs  in  strata  of  one  age  more 
than  another,  it  is  probably  one  of  those  things 
which  might  be  considered  as  accidental;  and 
ability  to  determine  and  classify  strata  by  their 
age  according  to  the  fossils  they  contain  is  not  of 
the  slightest  value  to  the  prospector.  Indeed 
geology  has  never  had  the  slightest  knowledge  of 
any  value  to  the  oil  man,  notwithstanding  many 
promotion  oil  companies  loudly  proclaim  that 
their  properties  are  recommended  by  some  "ex- 
pert geologist"  who  gives  a  long  dissertation 
of  his  "knowledge"  to  the  suckers;  and  of  his 
ignorance  to  the  rest  of  us.  There  are  many 
expert  oil  men  who  make  a  business  of  passing 
judgment  on  properties  for  others,  and  some  of 
them  prefer  to  be  called  geologists  to  which  we  can 
not  object,  but  the  odium  that  has  been  connect- 
ed with  the  term  of  late  would  seem  to  be  enough 
to  dissuade  any  from  attaching  it  to  their  names. 


ISOGEOTHERM  HYPOTHESIS 


d^  The  character  of  the  oil,  also,  does  not  seem 
to  be  affected  by  the  age  of  the  strata  in  which 
it  is  found;  for,  altho  the  great  bulk  of  the  high 
grade  oils  have  been  found  in  very  ancient  for- 
mations, and  nearly  all  the  large  production  of 
heavy  oils  is  produced  from  formations  of  recent 
age,  the  reverse  is  true  of  the  very  light  oils  of 
Java,  India,  and  Colombia,  S.  A.;  and  of  the 
rather  inferior  black  oil  of  western  Ohio  and 
eastern  Indiana. 

CL  The  similarity  in  appearance  of  the  strata  that 
is  so  noticeable  in  all  regions  where  petroleum  and 
other  carbonaceous  products  are  found,  could  only 
be  caused  by  the  degree  of  heat  and  pressure  to 
which  those  strata  in  which  these  products  are 
found  were  sub]  ected  at  the  time  of  their  maximum 
subsidence.  However,  petroleum  and  coal  bear- 
ing strata  of  great  age,  which  were  presumably 
subjected  to  pressure  of  the  superincumbent  strata 
for  long  ages,  are  firmer  than  are  those  of  recent 
age,  as  might  be  expected.  For  instance,  the 
shales  of  Pennsylvania,  among  which  petroleum 
and  coal  are  found,  are  much  harder  than  the 
shales  of  California  where  the  same  products 
occur,  but  the  same  general  appearance  and  color- 


twenty 


ISOGEOTHERM  HYPOTHESIS 


ing,  and  other  indescribable  conditions  prevail  in 
both  regions,  although  one  is  vastly  older  than 
the  other. 

^L  The  definite,  vertically  limited  oil-contain- 
ing horizons  of  California,  although  not  continu- 
ously productive,  occur  sometimes  in  considerable 
non-conformity  with  the  plane  of  stratification, 
and  sometimes  obliquely  cross  the  demarkations, 
where  one  series  of  deposits  rest  unconformably 
upon  another.  The  same  is  true  in  the  Appa- 
lachian and  middle  west  region,  where  the  imme- 
diate surface  for  a  thousand  to  two  thousand  feet, 
over  the  whole  country,  is  an  almost  unbroken 
petroleum  and  coal  horizon,  although  those  prod- 
ucts occur  in  separate  deposits,  or  groups  of  de- 
posits in  that  horizon,  often  widely  separated 
from  each  other.  That  the  successive  deposits,  do 
collectively,  in  their  continuance,  represent  on  a 
grand  scale  a  definite  limited  horizon,  which 
really  occurs  on  lines  of  a  former  isogeotherm, 
must  become  apparent  on  sufficient  consideration, 
altho  why  the  deposits  do  not  occur  more  con- 
tinuously in  that  horizon  has  never  been  satisfac- 
torily accounted  for. 


twenty-one 


ISOGEOTHERM  HYPOTHESIS 


HOW  COAL  OCCURS  IN  STRATA. 

CL,  Coal  also  occurs  in  a  horizon  which  in  its 
continuation,  is  independent  of  the  stratification. 
It  commonly  occurs  in  the  same  locality  with 
petroleum,  and  is  always  above  the  petroleum, 
usually  1000  to  1500  feet.  Sometimes  it  is  as 
much  as  2000  feet  above,  and  in  rare  instances, 
it  is  but  a  few  hundred  feet  above,  and  slight 
quantities  of  oil  have  been  known  to  seep  upward 
into  coal  mines  that  had  recently  been  opened. 
^L  The  petroleum  and  coal  horizons  always  par- 
allel each  other,  regardless  of  the  non-conformity 
of  their  horizons  to  the  plane  of  stratification, 
showing  that  the  relationship  between  them  is 
intimate,  as  could  not  be  otherwise;  for  in  the 
various  carbonaceous  products  resembling  either 
petroleum  or  coal,  it  is  difficult  to  draw  the  line, 
as  there  is  a  gradual  blending  of  one  into  the  other. 
C,  If  we  consider  the  limited  areas  of  coal 
regions,  and  the  still  more  limited  area  of  the 
known  oil-containing  territory  of  the  world,  we 
must  admit  that  if  these  two  products  occurred 
together  in  six  or  eight  different  regions,  it  would 
seem  more  than  a  coincidence.  But  when  we 
consider  that  nearly  all  the  petroleum  of  the 


twenty-two 


ISOGEOTHERM  HYPOTHESIS 


world    occurs    in  close    proximity  to   coal,    we 
may  justly  consider  the  fact  of  their  relationship 
to   be   firmly   established,   and   I   will  say   more 
about  this  phase  of  coal  and  oil  occurrence. 
CL  People  past  middle  age  who  have  been  inter- 
ested   in   geological  maps   have   noticed  that  the 
'"carboniferous"  areas  have  enormously  increased 
the  last  two  or  three  decades,  which  time   is  re- 
markably coincident  with  the  discovery  and  de- 
velopment   of    coal   all    over   the    world.      This 
stretching  of  the   carboniferous   over  what    was 
formerly  classed   as   permian,  and   devonian,  re- 
minds   me    of    the    professional    "oil    smellers. 
Those     good   old    uncles,  'who    formerly  used    a 
forked  peach  branch  to  "trace"  the  oil  belt,  now 
commonly  have  a   much  more   elaborate   and  en- 
tirely inexplicable  machine  to  prognosticate  with 
and  supply   a  long  felt  want   of  unsophisticated 
land   owners.      The   point  is   this:    the   "uncles 
display  wonderful  acumen  in  tracing  the  oil-con- 
taining belt  or  deposit,  in  so  far  as  it  has  already 
been   proven   by   the   pioneer  operator  with    his 
drilled  wells;  but  there  is   no  well  attested  case 
of    their    having    been    themselves    successful   as 
pioneers. 

twenty-three 


ISOGEOTHERM  HYPOTHESIS 


4L  The  extension  of  the  carboniferous  has  evi- 
dently teen  for  the  purpose  of  bolstering  up  the 
popular  (and  precarious)  notion  that  there  was 
once  an  age  or  period  of  extraordinary  develop- 
ment of  vegetation;  which  belief  was  in  its  turn 
necessary  to  bolster  the  popular  theory  that  coal 
represented  accumulated  vegetation  in  situ,  a 
theory  which  has  no  basis  in  fact,  as  I  intend 
to  show,  but  which  has  acquired  a  widespread 
acceptation  owing  to  a  mass  of  apparent  evidence 
which  has  appealed  strongly  to  the  superficial 
investigator,  and  owing  to  the  persistence  and  in- 
dustry with  which  this  apparent  evidence  has 
been  collected  and  advertised. 

d.  The  more  our  knowledge  of  this  old  earth 
accumulates  the  less  need  we  have  for  promul- 
gating theories  of  special  or  exceptional  condi- 
tions, and  the  writer  who  tells  us  of  wonderful 
catastrophies  in  the  dim  past,  no  longer  is  honor- 
ed above  those  who  can  only  see  evidence  of  an 
orderly  course  of  nature,  similar  to  what  we 
can  ohserve  in  our  own  short  time. 
CL  Coal,  like  petroleum,  occurs  in  strata  of  all 
ages  except  the  very  youngest  where  there  has 
not  been  sufficient  time  for  the  enormous  sub- 

t-wenty-four 


ISOGEOTHERM  HYPOTHESIS 


sidences,  and  subsequent  elevations,  with  the  at- 
tending erosion  which  is  necessary  to  bring  those 
products  within  our  reach. 

C[,It  is  popularly  telieved  that  hard,  or  anthra- 
cite coal  hecame  differentiated  from  other  coal 
hy  having  suhsided  to  a  great  depth  after  the 
carbon  became  fixed,  and  where  the  heat  oper- 
ated on  it. 

C,That  the  heat  operated  on  it  the  same  as  on 
other  coal,  and  no  more,  is  what  seems  to  be 
proven  by  anthracite  that  occurs  above  a  pe- 
troleum horizon  in  the  coast  country  of  Colom- 
bia, near  Barrenquilla,  South  America.  The 
coal  occurs  sparsely  at  several  places,  apparently 
600  or  800  feet  above  the  oil  horizon,  which 
latter  is  well  marked.  The  writer  did  not  ob- 
serve any,  or  hear  of  any  deposit  that  was  worth 
working,  but  it  is  there  just  the  same.  The 
strata  is  recent,  probably  tertiary. 
C,The  fact  that  sometimes  coal  is  hard,  at  other 
times  soft,  or  coking,  or  non-coking,  or  a  worthless 
lignite,  or  merely  a  manifestation  of  coal,  seems 
to  make  little  difference  in  regard  to  its  occur- 
rence in  orderly  horizons  and  its  relationship 
to  other  minerals,  and  the  deep  secrets  of  na- 

twenty-five 


ISOGEOTHERM  HYPOTHESIS 


ture  s  processes  are  beyond  our  ability  to  fathom 
at  present,  except  where  we  get  the  key  to  them 
in  the  plainest  manner. 

CL  1  here  has  been  much  microscopic  investigation 
of  coal,  with  a  view  of  studying  its  origin,  but 
it  is  safe  to  say  that  the  results  have  been  entire- 
ly unsatisfactory,  as  they  had  a  tendency  to  show 
that  each  different  stratum  was  formed  of  differ- 
ent matter.  This  is  exactly  what  might  be  ex- 
pected, for  coal  is  merely  ordinary  strata  that 
has  been  changed,  and  which  contains  more  or 
less  clearly  marked  impressions  of  the  coaser  debris 
that  the  original  sediments  contained,  the  finer 
lines  of  the  leaves  or  other  debris  being  some- 
times brought  out  by  the  black  particles  of  coal 
on  a  background  of  lighter  colored  shale,  in  a 
wonderful  manner. 

d^The  best  examples  of  this  seen  by  the  writer 
(who  has  worked  in  coal  mines,)  occurred  in  the 
shale,  with  only  fine  particles  of  coal  matter  to 
produce  the  markings,  and  as  other  strata,  even 
limestone,  contain  impressions  of  vegetation,  ap- 
parently as  frequently  as  coal,  why  are  not  those 
strata  coal,  if  such  evidences  of  original  vegeta- 
tion prove  the  accumulated  vegetation  theory? 

twenty-six 


ISOGEOTHERM  HYPOTHESIS 


n  some  ligmtic  coals  that  might  he  designated 
as  immature,  where  there  may  not  have  been 
sufficient  time  or  other  essential  conditions  to 
completely  form  the  carbonaceous  gases  into 
"fixed  carhon,  pieces  of  carbonized  wood  have 
heen  found,  being  of  such  a  nature  as  to  corres- 
pond with  the  rest  of  the  coal  seam.  It  is  noted, 
however,  that  when  wood  remains  are  found 
ahove  or  helow  the  coal,  they  are  almost  mvar- 
lahly  petrified,  silica  having  taken  the  place  of 
the  original  chemical  constituents. 
^Geologists  have  industriously  gathered  and 
placed  on  exhibition  many  exhibits  which  ap- 
parently evidence  the  correctness  of  the  com- 
pressed vegetation  theory,  and  a  museum  of  min- 
eralogy is  hardly  considered  complete  without 
one  of  them.  Almost  every  geologist  of  note 
has  gone  into  print  endorsing  the  idea,  which 
they  will  hardly  abandon,  until  the  oil  men  find 
it  universally  profitable  as  well  as  instructive  to 
search  for  oil  in  horizons  of  former  isogeotherm. 
CJn  the  Royal  Geological  Museum  on  Germyn 
Street,  London,  there  is  an  exceptionally  com- 
plete series  of  exhibits,  tending  to  show  that  coal 
is  compressed  vegetation,  and  if  one-half  of  the 


twenty-seven 


ISOGEOTHERM  HYPOTHESIS 


labor  and  ingenuity  had  teen  bestowed  upon 
stowing  tbat  coal  is  merely  cbanged  strata,  in 
wbicb  tbe  cbemical  constituents  bad  been  re- 
placed by  carbonaceous  matter,  and  tbat  tbe  ag- 
gregate occurrence  or  coal  in  its  continuance,  in 
any  region,  represented  a  former  isogeotberm, 
tbe  tbeory  would  bave  been  well  proven. 
d/Tbere  is  one  exbibit  in  particular,  in  tbe  Lon- 
don museum,  wbicb  is  wortb  mucb  study.  It  is 
intended  to  sbow  tbat  an  intrusion  of  gabbro  bad 
cbanged  tbe  nature  of  tbe  adjacent  coal,  but  to  a 
keen  observer  it  only  sbows  tbat  tbe  intrusion 
bad  occurred  before  tbe  coal  was  tbere.  Tbe 
coal,  wbicb  still  adbered  to  tbe  piece  of 
gabbro,  does  not  seem  to  bave  been  cbanged  by 
subsequent  beat,  its  exceptional  appearance  (it  is 
an  odd  looking  semi-antbracite  and  is  probably 
cbanged  gabbro)  baving  evidently  created  tbe  im- 
pression tbat  it  bad  been  cbanged  by  beat.  Had 
tbe  exbibit  consisted  of  a  large  portion  of  tbe 
coal  bed,  witb  some  of  tbe  intrusive  rock  at- 
tacbed,  it  would  bave  been  of  mucb  more  value. 
^Tbe  great  bulk  of  coal  strata  was  formerly  a 
soft,  massive  sbale,  or  bard  clay,  of  mucb  uni- 
formity of  texture,  wbicb  seems  to  bave  been 

twenty-eight 


ISOGEOTHERM  HYPOTHESIS 


best  adapted  to  arrest  and  receive  the  carbon- 
aceous matter,  out  in  exceptional  cases  apparent- 
ly any  kind  of  strata  turned  into  coal.  Even 
coarse  pebble,  tbe  waterworn  roundness  being 
well  preserved,  has  formed  coal. 
CL  A  popular  geological  writer,  who  of  course 
was  an  adherent  of  the  compressed  vegetation 
theory,  having  such  a  case  brought  under  his  ob- 
ssrvation,  says:  in  a  period  of  elevation,  the 
superincumbent  strata  must  have  been  eroded 
away,  and  the  coal  bed  cut  into  by  a  rivulet, 
which  formed  a  bed  of  waterworn  coal  pebbles 
in  the  coal  bed  itself:  after  which  the  region 
subsided,  and  was  covered  by  sediment  as  be- 
fore/ This  is  a  sample  of  the  immature  reason- 
ing that  has  established  a  theory  which  is  act- 
ually taught  in  our  schools.  First,  the  coal  was 
formed,  necessitating  a  covering  of  thousands  of 
feet  and  perhaps  millions  of  years  to  compact  the 
bed  of  vegetation  into  good  coal:  then  erosion, 
which  is  so  slow,  that  where  our  present  coal 
beds  have  been  cut  into  by  erosion,  it  requires 
a  practised  eye  to  determine  that  there  ever  was 
a  coal  bed  there,  and  the  "blossom"  has  to  be 
traced  by  drifting,  often  for  a  hundred  yards 

twenty-nine 


ISOGEOTHERM  HYPOTHESIS 


from  the  surface,  before  any  coal  good  enough 
for  use  can  be  obtained,  the  outcrop  having  been 
destroyed,  or  deteriorated,  by  access  of  air. 
It  is  well  known  that  the  best  commercial  coal 
deteriorates  in  value,  by  being  stored  in  the  open 
air,  and  for  this  reason  arrangements  are  being 
made  to  store  it  under  water.  But  entirely  ob- 
livious of  the  perishability  of  coal,  this  ""author- 
ity  had  the  coal  actually  worn  into  pebbles  by 
slow  erosion,  and  then  covered  up  by  the  set- 
tlings of  erosion,  without  affecting  the  quality. 
CL  The  popular  hypothesis  of  coal  origin  as  pro- 
mulgated by  the  geologists  of  the  last  few  decades 
is  quite  definite,  and  I  think  that  I  will  not  be 
charged  with  unfairness  when  I  state  that  it 
supposes  each  bed  or  vein  of  coal  to  repre- 
sent an  accumulation  of  vegetation  on  the  ground 
on  which  it  grew:  after  which,  the  region  sub- 
sided, and  was  covered  with  sediment  which  be- 
came the  soil  in  which  another  accumulation  of 
vegetation  grew,  when  the  region  again  emerged, 
etc.  Those  theorists  neglected  to  make  pro- 
vision for  preserving  a  sufficiency  of  vegeta- 
tion from  decay  pending  its  submergence  under 
the  ocean,  and  when  we  consider  the  perishable 

thirty 


ISOGEOTHERM  HYPOTHESIS 


nature  of  coal  itself,  to  say  nothing  of  vegeta- 
tion, the  idea  seems  absurd. 

CL  The  immense  amount  of  carbon  contained  in 
a  large  coal  vein,  and  the  small  amount  contained 
in  a  yearly  growth  of  vegetation,  must  have 
rather  queered  the  gentlemen,  for  they  agreed 
that  it  took  an  enormously  long  time,  which  they 
reckoned  into  the  hundreds  of  thousands  of 
years,  during  which  time  the  mass,  which  must 
often  have  been  hundreds  of  feet  in  thickness, 
was  in  some  inexplicable  manner  preserved  from 
decay. 

C,  Now,  the  accumulation  of  such  an  immense 
amount  of  carbon  by  growth  is  an  utter  impos- 
sibility, owing  to  the  limitation  of  fertility  of 
the  soil.  Any  good  farmer  can  tell  you  that 
without  the  application  of  matter  containing  cer- 
tain salts,  the  best  soils  would  become  unpro- 
ductive, if  heavy  crops  were  taken  off  continu- 
ously. Before  the  vegetation  would  suffici- 
ently decay  for  the  salts  to  become  again  avail- 
able, the  carbon  matter  would  all  have  escaped 
into  the  atmosphere.  Then  again,  the  large 
number  of  subsidences  and  elevations  that,  in 
some  caaes,  would  have  to  occur  successively, 

thirty-one 


ISOGEOTHERM  HYPOTHESIS 


during  the  building  up  of  a  very  small  amount 
of  strata,  is  hardly  consistent  with  our  under- 
standing of  such  phenomena. 

CL  The  helief  in  the  accumulated  vegetation 
theory,  seems  to  he  based  mainly  on  the  fact 
that  fossil  impressions  of  vegetation  are  found  to 
occur  in  coal,  but  they  also  occur  intermittently 
in  the  whole  series  of  deposits  in  which  the  coal 
occurs,  as  frequently  as  they  do  in  the  coal.  In 
some  coal,  no  fossil  vegetation  whatever  can  be 
detected,  in  other  coal  it  is  common.  The  same 
is  true  of  the  shales.  Many  geological  writers 
have  stated  that  coal  measures  (which  term,  if  it 
means  anything,  means  the  coal  containing  hori- 
zon) were  many  thousands  of  feet  in  thickness, 
but  we  must  consider  their  methods  of  deter- 
mining the  thickness,  which  was  by  aggregating 
the  thickness  of  all  the  strata  in  which  coal  oc- 
curred at  any  point.  Had  the  result  been  deter- 
mined by  drilling  a  deep  well  at  any  point  that 
they  might  have  selected  in  the  coal  regions,  they 
undoubtedly  would  have  found  that  the  whole 
horizon  or  coal  occurrence  would  have  been  con- 
fined to  a  f ew  hundred,  or  at  most,  a  thousand  feet. 
CL  But  the  feature  of  the  geologists  theory  of 

thirty-two 


ISOGEOTHERM  HYPOTHESIS 


coal  orig'm,  that  is  most  opposed  to  reason,  how- 
ever,  is,  the  emergence  of  those  thin  sheets  of 
clay  strata  between  some  of  the  minor  coal 
seams,  which  strata  are  sometimes  only  a  few 
inches  in  thickness,  and  extend  over  large  areas, 
and  which,  before  they  had  hundreds  of  feet  of 
covering  were  nothing  hut  slimy  pulp  like  occurs 
now  on  the  bottom  of  the  deep  ocean,  the  only  place 
where  clayey  shales  are  formed.  The  absolutely 
uniform  texture  of  those  shales  would  prohibit 
their  formation  in  a  lagoon,  or  in  any  other  place 
whatever,  except  on  the  bottom  of  a  very  deep 
ocean,  at  a  great  distance  from  shore,  and  it  is 
too  much  to  suppose  that  in  their  emergence  they 
would  survive  the  wave  erosion,  of  which  I  will 
speak  further  on.  Some  geologists  think  that  coal- 
beds  represent  accumulations  of  driftwood,  but 
this  theory,  also,  presents  insurmountable  diffi- 
culties, as  it  -would  require  the  postulation  of 
conditions  enormously  different  from  any  we 
know  of.  But  it  is  not  necessary  to  further  dwell 
on  the  absurdities  of  the  compressed  vegetation 
theory,  altho  a  book  might  be  filled  with  them. 
d.  Coal  sometimes,  especially  in  much  disturbed 
mountain  regions,  occurs  in  immense  masses,  m 

thirty-three 


ISOGEOTHERM  HYPOTHESIS 


very  limited  areas.  The  name,  "horse  halls 
applied  to  one  series  of  them,  will  give  the  reader 
some  idea  of  their  form,  which  however  is  gener- 
ally irregular.  In  most  of  such  occurrences  of 
coal,  it  is  plain  that  there  is  little  or  no  con- 
formity of  the  coal,  to  the  plane  of  stratification. 


Stratag'raphy  of  the  west-end  Whittier  oil  field  looking  east — 
further  S.  E.  the  dip  is  not  so  great.  Light  lines  represent  the 
bedding;  short  heavy  lines  represent  oil  deposits,  which,  in  their 
aggregate  continuance,  form  the  oil  horizon,  which  represents 
a  former  isogeotherm. 

d^  But  there  is  hardly  a  coal-bed,  or  vein  any- 
where, that  does   not  display  in  some  portion  of 

thirty-four 


ISOGEOTHERM  HYPOTHESIS 


its  extent,  some  unconformity  to  the  bedding,  and 
I  wish  to  call  the  reader's  attention  particularly 
to  this  point.  It  must  be  apparent  to  the  care- 
ful student  that  if  this  is  true,  it  alone,  must  es- 
tablish the  origin  of  coal  in  the  manner  herein  set 
forth.  If  you  enter  a  coal  mine  in  the  Pittsburg, 
Pa.,  district,  and  travel  towards  the  south,  you  will 
notice  by  observing  carefully,  that  the  coal  en- 
croaches gradually  on  the  strata  above,  and  cor- 
respondingly vacates  the  strata  below,  until  in 
the  course  of  half  a  mile  or  so,  the  whole  vein 


Diagram,  showing  the  prospector  how  the  successive  occurrences 
of  petroleum  and  coal  are  likely  to  appear  on  both  sides  of  the 
same  anti-cline. 

will  be  in  different  strata  from  where  you  first 
observed  it.  In  other  coal  fields,  where  this 
non-conformity  to  the  stratification  is  much 
greater,  and  the  separate  veins  or  beds  of  much 
less  extent,  the  field  is  a  succession  of  veins  oc- 
curring in  a  series  of  benches  or  steps,  generally 
overlapping  each  other,  each  vein  conforming 

thirty-fire 


ISOGEOTHERM  HYPOTHESIS 


fairly  well  to  the  stratification,  out  the  whole 
field  throughout  its  continuance  being  sometimes 
as  much  as  20  degrees  out  of  parallel  with  the 
stratification.  It  is  in  such  cases  as  this  that 
careless  investigators  have  stated  that  the  coal 
occured  throughout  a  horizon  of  thousands  of 
feet,  when  in  reality  the  actual  horizon  of  coal 
occurrence  did  not  exceed  a  few  hundred  feet. 
CL  Now,  the  only  logical  deduction  that  can  he 
made  in  regard  to  this  occurrence  of  coal  (and  other 
mineral)  in  an  orderly  limited  horizon,  independ- 
ently of  the  stratification,  is,  that  it  was  formed 
subsequently  to  the  formation  of  the  strata  with 
which  it  is  blended,  and  at  the  time  of  maximum 
subsidence  of  the  region,  the  coal  field  as  a  whole, 
was  spread  out  approximately  horizontal,  parallel 
with  the  surface,  but  the  stratification  was  not. 
(Strata  of  any  considerable  age  is  never  exactly 
horizontal.)  Chemical  investigation  or  a  series  of 
strata  m  which  coal  occurs,  shows  us  that  there  is  a 
great  excess  of  free  silicates  in  the  strata  adjoin- 
ing the  coal.  The  same  is  often  true  of  iron 
ore.  The  shiny,  greasy  appearance  of  the  cleav- 
age is  a  manifestation  of  this  change  in  chemical 
structure.  Most  of  the  valuable  fire-clays,  ka- 

thirty-six 


ISOGEOTHERM  HYPOTHESIS 


olins  and  soap-stones  or  commerce,  accompany 
coal  and  iron  ore  in  their  occurrence,  snowing 
us  the  chemical  changes  that  occurred,  when  the 
silicates,  etc.,  were  forced  to  vacate  the  strata, 
as  the  latter  was  taken  possession  of  hy  the  car- 
oonaceous  matter  in  its  concentration. 
^L  If  you  take  a  good  encyclopedia,  and  look 
over  the  mineral  reports  of  various  countries, 
like  for  instance,  the  Spanish  American  coun- 
tries, where  adverse  governmental  conditions 
have  heretofore  prevented  exploitation,  you  may 
fce  surprised  at  the  large  numter  of  regions  that 
are  reported  to  contain  "coal  and  petroleum,"  or 
"coal  and  traces  of  petroleum.  If  you  investi- 
gate further,  you  will  almost  invariahly  find 
that  toth  these  products  occur  in  the  same  re- 
gion, most  commonly  in  the  same  locality,  and  a 
personal  investigation  -will  disclose  that  those  pro- 
ducts occur  in  the  same  general  horizon,  with  the 
coal  above  the  petroleum,  and  this,  notwithstand- 
ing that  the  strata  in  which  those  minerals  oc- 
cur, are  of  the  greatest  variety  of  geologic  age. 
4L  In  some  petroleum  regions,  there  are  only 
slight  traces,  or  manifestations  of  coal,  so  far  dis- 
covered; and  in  some  coal  regions,  perhaps  the 

thirty-seven 


ISOGEOTHERM  HYPOTHESIS 


oil  is  not  in  sufficient  quantity  to  be  profitable, 
but  this  sbould  not  detract  from  the  significance 
of  the  apparent  relationship. 

4L  In  Great  Britain,  petroleum  occurs  in  small 
quantities  under  the  coal  at  some  points,  but  it 
is  of  little  value,  being  mostly  of  the  oil  shale 
variety,  which  has  to  be  mined  before  it  can  be 
distilled.  It  is  here  that  the  coal  bearing  de- 
posits, being  confined  within  narrow  geological 
limits,  first  gave  the  name  "carboniferous  to 
the  strata.  The  most  important  of  the  North 
American  coal  deposits  were  then  exploited,  and 
it  so  happened  that  they  were  in  strata  of  simi- 
lar age,  as  nearly  as  could  be  determined;  and  it 
was  then  that  the  belief  was  formed,  that  there 
could  be  no  coal  of  any  considerable  value,  out- 
side of  that  series  of  rocks,  and  it  began  to  be 
noticed  that  there  seemed  to  be  a  relationship 
between  the  coal  and  petroleum.  However, 
there  was  no  getting  around  the  fact  that  the 
Appalachian,  and  Middle  \Vest  important  coal 
deposits  occurred  throughout  a  stratagraphic  scope 
of  many  thousands  of  feet,  with  the  oil  paralleling 
the  coal  at  some  hundreds  of  feet  below.  The 
coal  of  \Varren  and  McKean  counties,  in 

thirty-eight 


ISOGEOTHERM  HYPOTHESIS 


northern  Pennsylvania,  occurs  in  a  plane  of  stra- 
tification, which,  if  continued  south,  would  un- 
derly  the  various  oil  containing  strata  in  south- 
west Pennsylvania.  No  coal,  however,  was 
ever  found  under  oil,  despite  the  fact  that  many 
deep  (hut  futile)  wells  were  drilled  in  middle 
and  southwestern  Pennsylvania  in  search  of  the 
oil,  which,  it  was  thought,  ought  to  occur  in 
continuation  of  the  plane  of  stratification  of  the 
northern  oil  deposits. 

^i,  In  connection  with  this  parallelism  of  the 
coal  and  oil  horizons,  it  is  well  to  rememher  that 
in  many  oil  fields,  the  oil  occurs  too  near  the 
surface  to  admit  of  a  coal  horizon  above  it,  the 
strata  where  the  coal  belonged  having  been 
eroded  away  ages  ago. 

4L  No  doubt  the  same  coal  horizon  is  represent- 
ed by  the  coal  of  Pennsylvania,  Ohio,  Michigan, 
Indiana,  Alabama,  Kentucky,  Virginia,  ^Vest 
Virginia,  Tennessee,  Illinois,  Missouri,  Iowa, 
Kansas,  Oklahoma,  Texas,  and  perhaps  other 
states.  Oil  occurs  under  the  coal  in  all  these 
states  with  the  possible  exception  of  Michigan. 
The  strata  in  which  these  products  occur,  in  this 
great  area,  can  not  by  any  stretch  of  the  imagin- 

thirty-nine 


ISOGEOTHERM  HYPOTHESIS 


ation  be  considered  syncronous,  or  continuous, 
and  altho  the  coal  and  oil  occur  in  patches  only, 
with  often  wide  areas  that  are  barren,  there  can 
be  no  doubt  that  they  represent  on  a  grand  scale, 
a  former  isogeotherm  throughout  this  immense 
region. 

CL  Petroleum  also  occurs  under  coal,  in  \Vy- 
oming  and  Utah:  and  at  several  places  in  Cali- 
fornia, coal  of  an  inferior  kind  occurs,  if  not 
directly  ahove  the  oil,  at  least  in  continuation  of 
the  general  horizon  of  carhonaceous  products. 
CL  I  wish  particularly  to  call  attention  to  the 
occurrence  of  coal  in  parallelism  with  petroleum 
throughout  regions  having  surface  strata  of  var- 
ious ages,  and  the  continuance,  or  at  least  core- 
lation  of  the  coal  or  petroleum  horizons  in  strata 
of  one  age,  to  strata  of  a  different  age  in  ad- 
joining locality  or  region.  Also  to  the  fact  that 
the  horizons  of  those  products,  altho  each  may 
consist  of  several  deposits  overlying  each  other, 
both  maintain  their  identity,  and  maintain  an 
orderly  distance  apart  over  a  considerable  re- 
gion. 

4^  ^A^here  the  oil  containing  horizon  has  a  con- 
siderable scope,  the   coal  horizon  also,  has  a  con- 
forty 


ISOGEOTHERM  HYPOTHESIS 


sideratle  scope,  and  the  two  maintain  a  great 
distance  apart;  as  in  southwest  Pennsylvania,  and 
northern  Vv  est  Virginia,  where  the  two  horizons 
are  about  2,000  feet  apart  from  center  to  center. 
In  Illinois,  where  there  is  only  a  few  hundred 
feet  between  them,  the  coal  and  petroleum  are 
each  confined  to  one  or  two  deposits  close  together. 
4^  Many  textbooks  and  geological  reports  and 
bulletins,  altho  edited  by  persons  who  "never 
looked  at  it  that  way,"  are  useful  in  showing 
that  oil  and  coal  occurrences  in  their  aggregate 
continuance,  represent  former  isogeotherms. 
4^  Most,  if  not  all  the  metallic  minerals,  seem  to 
occur  in  horizons,  independently  of  the  plane  of 
stratification,  like  petroleum  and  coal.  That  is, 
each  deposit  of  exactly  like  variety,  (if  there  be 
any  two  such  in  nature)  has  required  like  con- 
ditions of  covering,  heat,  and  other  like  condi- 
tions of  environment.  Carbonate  iron  ores:  hem- 
atite, limonite,  magnetite,  etc.,  in  infinite  variety, 
occupy  a  definite  position  in  relation  to  each 
other  and  to  coal,  lying  above  the  coal  at  vary- 
ing distances  according  to  type,  while  another, 
and  vastly  different  kind  of  iron  occurs  well 
down  in  the  metamorphic  rocks,  where  the  heat 

forty-»ne 


ISOGEOTHERM  HYPOTHESIS 


was  evidently  sufficiently  great  to  deposit  it  in 
a  volatile  condition  analogous  to  our  treatment  of 
iron  in  the  arts.  The  before  mentioned  iron 
ores  which  are  plainly  deposits  of  former  gravel 
and  sandrock,  the  substance  of  which  has  turned 
more  or  less  into  iron,  may  be  said  to  be  of 
"chemical"  origin,  but  the  fact  that  they  occur 
in  a  definite  limited  horizon,  independently  of 
the  plane  of  stratification,  shows  that  their  oc- 
currences represent,  in  their  continuance,  a  form- 
er isogeotherm.  The  carbonate  iron  ores  are 
popularly  supposed  to  be  precipitates  from  iron- 
charged  water  that  percolated  into  the  strata 
that  afterwards  became  iron,  but  consideration 
of  the  fact  that  coal  and  iron  carbonates  so  fre- 
quently occur  together,  must  show  that  there  is 
a  relationship  between  them. 

(^  Limestones  of  like  type  also  occur  in  limited 
horizons:  and,  while  a  massive  limestone  deposit 
may  closely  adhere  to  the  plane  of  stratification 
for  a  hundred  miles,  if  it  has  extended  out  of 
conformity  with  the  former  isogeotherm,  it  will 
have  changed  its  type;  and  as  like  as  not  another 
deposit,  500  or  1000  feet  above  or  below  the 
first,  -will  have  developed  into  the  original  type 

forty-two 


ISOGEOTHERM  HYPOTHESIS 


of  the  first  deposit,  defining  the  course  of  the 
former  isogeotherm.  It  is  more  common,  how- 
ever for  a  massive  limestone  to  occur  out  of  con- 
formity 'with  the  heading,  when  people  who  do 
not  suspect  its  true  nature  often  use  it  as  a  hase 
for  the  determination  of  the  position  of  other 
strata,  with  much  confusion  of  understanding. 
CL  The  text-books  tell  us  that  limestone  is  main- 
ly or  largely  composed  of  the  remains  of  marine 
creatures  that  lived—and  died — in  great  numbers 
at  the  time  the  said  limestone  was  forming  at  the 
bottom  of  the  ocean.  But  much  contemplation 
and  observation  of  limestone,  (which  is  a  very  in- 
definite term,)  shows  us  that  it  does  not  contain 
evidences  of  marine  forms  in  greater  number,  or 
more  frequently  than  other  sedimentary  strata. 
CL  It  is  common  to  see  massive  limestone,  very 
pure  and  hard,  without  a  trace  of  marine  forms 
throughout  its  extent,  while  a  few  hundred  feet 
under  it  will  be  found  shales,  sands  and  con- 
glomerates, containing  numerous  shells  of  marine 
creatures,  composed  not  of  lime,  but  or  silica. 
The  Niagara  limestone  at  Niagara  Falls  is  typi- 
cal of  the  kind  that  occurs  so  frequently  in,  or 
just  above  the  petroleum  horizons.  To  the 

forty-three 


ISOGEOTHERM  HYPOTHESIS 


southwest  for  hundreds  of  miles,  the  "Niagara" 
maintains  its  type  because  it  conforms  to  the 
lines  of  a  former  isogeotherm,  tut  to  the  south, 
it  soon  loses  its  identity,  because  it  dips  below 
the  oil  horizon.  The  mile-deep  well  near  Pitts- 
burgh did  "not  reach  it,  to  the  astonishment  of 
the  geologists. 

CL  ^Vhere  carbonate  of  lime  is  abundant  in  the 
horizons  of  coal  and  petroleum,  it  has  changed 
shales  into  hard  dolomites  or  other  hard  lime- 
stones; sand  has  been  turned  into  sandstones;  peb- 
bles have  been  turned  into  conglomerates;  etc. 
Four  or  five  thousand  feet  higher  in  the  series  it 
occurs  in  a  more  or  less  chalky  form,  often  in 
the  form  of  concretions,  which  occurrence  would 
absolutely  forbid  their  formation  by  accumula- 
tion of  limy  marine  shells.  Many  other  forms 
of  limestone  occur  so  irregularly  as  to  utterly 
preclude  their  formation  in  this  way.  If  lime 
can  leave,  or  be  driven  out  of  fossil  shells  through 
chemical  action,  can  it  not  be  driven  indefinite 
distances  through  strata,  to  redeposit  in  strata 
containing  no  trace  of  marine  forms? 
CL  Did  petroleum,  coal,  limestones  of  similar 
type,  and  other  products,  occur  evenly  and  con- 

forty-four 


ISOGEOTHERM  HYPOTHESIS 


tiimously  in  their  proper  horizons,  then,  the  fact 
of   thsir   occurrence    on  lines  of   former  isogeo- 
therms  would  he  self -evident,  tut  that  perplexing 
old   alchemist,  the   earth,    has   grouped   them   in 
such   an  irregular   way,    owing    to    causes    that 
are   not  yet   understood,   that   it    requires   quite 
an    application  to  the  subject  to  properly 
view     them     in     this     regard.       Sometimes 
the   carbonaceous  matter  in  a  series  of  deposits 
has    apparently    all,   or  nearly   all,   entered   into 
combinations    to    form    a    limestone    of   massive 
form.      At  other   places   it  has   gone  almost  ex- 
clusively   into    an    immense    coal   vein,    or   into 
a   number    or  coal   veins  or  beds,  occurring   one 
above   another,   sometimes   several    hundred    feet 
apart,  and  varying  in  their  character  of  compo- 
sition, which  probably  accounts  for  their  position 
vertically    in    the   zone    or    horizon.      At    other 
places,  nothing  but  petroleum  is  in  evidence,  (this, 
however,    is   rare.)      Elsewhere,   salt    alone,    or 
iron    carbonates    are    found.       Vv  here    all,    or 
several    of    these   products    occur,    they    always 
occur  in  their  regular  order,  the  petroleum  oc- 
curs below  the   coal,  the  salt  between  the  two, 
or  possibly   sometimes  below  the  oil.      The  iron 

forty-five 


ISOGEOTHERM  HYPOTHESIS 


ore,  if  a  typical  hematite,  closely  adheres  to  the 
zone  of  the  coal,  but  if  a  limonite.  it  may  occur 
2000  or  3000  feet  above  it.  Limestones  of  like 
type  always  are  confined  to  a  certain  position  in 
relation  to  the  other  products,  but  being  of  vari- 
ous degrees  of  pureness  and  composition,  they  of 
course  have  a  range  vertically  of  many  thousands 
of  feet,  as  might  be  expected. 

d,  Many  other  non-metallic  minerals  of  like 
type  occur  in  definite  limited  horizons,  independ- 
ently of  the  plane  of  stratification.  Mineral 
nitrates  occur  in  this  way.  Their  occurrence 
in  quantity  is,  however,  limited  to  regions  where 
there  is  very  little  or  no  rainfall,  as,  if  there 
was  enough  water  to  reach  down  in  the  earth, 
it  would  quickly  dissolve  the  valuable  salts. 
Common  salt,  soda,  etc.,  are  found  outcropping 
only  in  desert  countries  for  the  same  reasons, 
but  are  now  largely  obtained  by  shafting  or  bor- 
ing through  impervious  superincumbent  strata, 
below  the  point  where  the  water  has  penetrated, 
because,  of  course,  there  was  no  water  in  those 
zones  or  isogeotherms,  until  they  emerged  and 
were  eroded,  the  original  sea  water  with  which 
they  were  charged,  when  they  were  formed, 

forty-fix 


ISOGEOTHERM  HYPOTHESIS 


having  teen  dissipated  as  suck,  before  they  had 
reached  their  maximum  subsidence, 
d.  The  most  common  form  of  salt  occurs  in 
petroleum  and  coal  horizons,  sometimes  in 
such  enormous  quantities,  and  in  such  purity, 
that  the  popular  conception  of  its  origin  in  desert 
basins  must  be  wrong.  \Vater  found  at  great 
depths  is  almost  invariably  charged  with  some 
kind  or  other  of  salts  which  make  it  unfit  for 
use.  Close  to  the  surface  however,  especially 
above  the  level  of  the  deeper  valleys,  the  cir- 
culation of  the  water  in  countries  having  a  fair 
amount  of  rainfall,  has  removed  the  salts.  All 
this  evidences  the  truth  of  the  theory,  that  the 
strata  had  subsided  to  where  the  heat  or  other 
factors  of  great  depth  and  pressure,  had  operated 
to  eliminate  the  uniformly  brackish  sea  water 
that  saturated  the  sands  when  the  strata  was 
formed.  Sulphur  and  other  substances  that  blend 
with  coal,  petroleum  and  many  other  products, 
could  only  have  done  so  in  a  condition  of  volati- 
lization. 

d.  Soils  also,  might  advantageously  be  classified 
along  lines  of  former  isogeotherms. 

£orty-»eve» 


ISOGEOTHERM  HYPOTHESIS 


VERTICAL  EXTENT  OF  MINERAL 
HORIZONS 

^  All  Jeep  well  drillers  know  by  practical  ex- 
perience, that  the  heat  increases  downward,  but 
in  some  regions  it  increases  much  more  rapidly 
than  in  others.  Unless  a  flow  of  water  is  en- 
countered, it  is  difficult  to  get  the  exact  temper- 
ature of  a  hole  at  any  point,  because  the  cool 
water  that  is  constantly  admitted  to  the  hole,  has 
a  tendency  to  cool  the  rock,  which,  being  a  non- 
conductor of  heat,  is  slow  and  uncertain  about 
recovering  its  normal  temperature. 
4L  ^vVhere  the  heat  increases  rapidly,  it  is 
thought  to  be  owing  to  the  strata  being  of  a  less 
complete  non-conductive  nature,  than  where  it 
increases  slowly. 

Ci^  No  doubt  this  variation  in  the  increase  of 
heat  applies  to  great  depths  as  well  as  to  the  in- 
significant depth  of  a  few  thousands  of  feet  to 
^which  we  can  penetrate  with  our  present  facili- 
ties. 

d^  If,  at  the  time  of  maximum  subsidence  of  a 
region,  the  heat  increased  rapidly  in  the  isogeo- 
therm  of  deposition  of  volatilized  carbonaceous 
matter,  then  we  should  expect  to  find  the  result- 

forty-eight 


ISOGEOTHERM  HYPOTHESIS 


ing  products  confined  to  a  few  hundred  feet  ver- 
tically in  each  case,  altho  there  would  he  other 
factors,  such  as  the  presence  of  other  substances 
with  which  each  product  would  have  a  tendency 
to  hi  end. 

d.  If  the  heat  increased  slowly,  we  should  ex- 
pect the  coal  for  instance,  to  occur  in  a  consid- 
erable vertical  scope,  a  thousand  feet  in  some  ex- 
treme cases,  like  for  instance,  southern  Pennsyl- 
vania, or  northern  \Vest  Virginia,  where  the 
oil  likewise  occurs  a  couple  of  thousand  feet  he- 
low  the  coal,  and  like  the  coal,  has  a  consider- 
able scope. 

CL  \Ve  must  not  forget  about  the  enormous  de- 
nudation that  has  occurred  almost  everywhere, 
at  least  wherever  there  is  a  semblance  of  hills  or 
uneveness  of  any  kind.  The  present  surface 
lines  in  an  oil  or  coal  horizon,  or  region,  should 
be  regarded  largely  as  an  accidental  circumstance. 
^Ve  frequently  see  a  thousand  feet  thickness  of 
strata  outcropping  in  plain  view,  the  upper  por- 
tion of  which  is  apparently  as  firmly  knit  by  the 
former  pressure  as  the  bottom  layers  are.  This 
shows  that  the  weight  of  the  one  thousand  feet 
of  strata  was  such  a  small  part  of  the  whole 

forty-mac 


ISOGEOTHERM  HYPOTHESIS 


pressure  to  which  the  strata  had  originally  been 
subjected,  that  it  made  no  appreciable  differ- 
ence to  our  eyes.  If  however,  we  have  an  op- 
portunity of  observing  a  few  thousand  feet  ad- 
ditional of  outcrop  above  the  other  thousand,  we 
will  probably  be  able  to  note  a  difference,  ow- 
ing to  an  increase  in  firmness  as  we  trace  the 
strata  downward. 

d.  Near  the  Hill  street  tunnel,  on  First  street, 
Los  Angeles,  Cal.,  there  is  beautifully  exposed, 
strata  tilted  almost  vertically,  resting  upon  which, 
unconformably,  of  course,  is  a  horizontal  strata, 
-which  is  not  much  less  firm  than  the  lower  one. 
Both  series  are  among  the  most  recent  deposits, 
and  constitute  an  object  lesson  of  the  immensity 
of  past  time. 

d,  ^*Ve  must  remember  that  where  we  can  trace 
a  single  series  of  30,000  feet  or  so  of  strata,  we 
must  look  for  the  petroleum  and  coal  horizons 
near  the  top  of  the  visible  series,  because  the 
comparatively  f ew  thousands  of  feet  or  material 
that  had  been  above  them  would  be  more  crumb- 
ly and  less  compact,  and  hence  not  likely  to  sur- 
vive the  denudation  that  had  exposed  the  im- 
mense series  of  strata.  Likewise  when  we  ob- 

fifty 


. 

ISOGEOTHERM  HYPOTHESIS 


serve  a  flat,  or  gently  rolling  landscape,  composed 
of  crumbly  material,  where  the  bedding  can  only 
be  detected  in  tne  most  favorable  locations,  we 
may  be  sure  that  the  valuable  minerals,  if  any, 
are  far  below,  excepting,  of  course,  in  a  possible 
separate  series  of  deposits  within  react  of  tbe 
surface. 

CL  \Vbile  petroleum  is  confined  to  a  definite 
vertically  limited  borizon  wbicb,  like  coal,  oc- 
curs independently  of  tbe  stratification,  it  does  not 
occur  so  regularly  in  that  borizon,  being  collect- 
ed more  in  spots,  or  irregular  belts,  and  rarely 
spreads  continuously  over  a  considerable  stretcb 
of  country.  Tbe  fact  tnat  petroleum  only  oc- 
curs in  porous  strata,  often  very  limited  and  ir- 
regular in  occurrence,  also,  probably  bas  mucb 
to  do  with  its  irregular  occurrence. 
4L  All  who  have  read  geological  textbooks  and 
official  bulletins,  may  have  noticed  that  the 
writers  or  editors  sometimes  described  certain 
conditions,  admitting  that  they  were  perplexing 
and  inexplicable,  but  which  are  not  so  at  all, 
when  considered  in  connection  with  the  isogeo- 
therm  hypothesis.  Several  geological  writers 
have  stated  that  it  was  "a  curious  fact"  that  in 

fifty-one 


ISOGEOTHERM  HYPOTHESIS 


the  Appalachian  region,  or  at  least  certain  por- 
tions of  it,  the  petroleum,  or  coal,  in  their  successive 
occurrences  in  a  certain  direction,  occurred  suc- 
cessively higher,  and  in  younger  strata,  or  the 
reverse,  over  several  hundred  miles  in  one  direc- 
tion. It  has  teen  admitted  that  cross-bedding, 
and  other  phenomena,  in  strata  that  only  admit- 
ted of  certain  definite  conditions  in  their  forma- 
tion, occurred  in  hoth  coal  and  limestone.  Of 
course,  there  is  nothing  wonderful  in  this,  when 
we  regard  hoth  of  these  products  as  merely  pro- 
miscuous ordinary  strata  that  has  teen  changed 
in  its  chemical  contents  only,  but  the  old  geologi- 
cal conception  of  their  origin  requires  the  per- 
formance of  miracles  in  their  behalf. 

STRATIGRAPHY    OF    THE  WHITTIER 
OIL  FIELD 

CL  The  stratigraphy  in  connection  with  the  oil 
occurrences  in  the  old  \Vhittier  oil  field,  al- 
though possessing  certain  general  features  in  com- 
mon with  all  other  oil  producing  districts,  con- 
tains those  fundamental  features  in  such  an  exag- 
gerated aspect,  that  the  determining  of  the  law 
of  the  oil  occurrence  has  seemed  inexplicable  and 


ISOGEOTHERM  HYPOTHESIS 


past  finding  out,  and  while  perhaps  no  other  oil 
field  has  he  en  so  much  studied  and  described,  it 
will  perhaps  interest  many  to  get  still  another 
description,  and  general  deductions  from  my  obser- 
vations, because,  perchance,  they  ""never  looked 
at  it  that  way. 

41,  The  trend  of  the  exposed  strata  in  this  field, 
is  found  by  much  investigation,  to  average  a  true 
east  and  west,  but  as  the  developed  portion* 
•which  is  well  defined  by  numerous  failures  (at 
least  on  its  northeast  side,)  extends  in  a  nearly 
northwest  and  southeast  direction,  and  is  very 
restricted  in  width,  at  least  in  its  northwest  end, 
owing  to  the  steep  dip  of  the  oil  horizon,  it  is 
obvious  that  oil  occurrence  along  the  line  of 
strike  of  the  strata  is  not  very  extended,  and  sel- 
dom reaches  as  much  as  half  a  mile. 
4L  This  is  the  feature  that  was  so  puzzling  to 
the  early  operators,  and  many  investors  still  have 
an  aching  void  in  the  region  of  their  pocketbooks, 
owing  to  failure  to  locate  producing  wells  a  short 
distance  along  the  line  of  strike  of  the  strata  from 
good  producers. 

CL  It  might  be  supposed  that  whatever  was  the 
cause  of  this  general  unconformity  of  the  course 

fifty-three 


ISOGEOTHERM  HYPOTHESIS 


or  the  oil  belt  to  the  trend  or  strike  of  the  strata, 
the  continuance  of  porosity  in  many  of  the  oil 
strata,  in  ohliquely  crossing  the  narrow  field, 
would  cause  great  irregularities  in  the  flanks  of 
the  general  oil  belt.  But  this  is  not  the  case, 
the  limits  of  the  field  being  fairly  regular,  as 
represented  by  developments,  oil  seepages,  and 
other  surface  indications;  one  exception,  how- 
ever, being  a  considerable  seepage  midway  of  the 
field,  and  near  the  line  of  the  southwestern  edge 
of  developments,  the  rest  of  the  seepages  being, 
of  course,  on  the  other,  or  shallow  side. 
CL  There  has  not  been  a  single  failure  in  the  de- 
fined field,  except  such  wells  as  were  pinched  out, 
or  plugged  -with  lost  tools,  or  by  failure  to  shut  off 
the  water,  while  close  outside  the  defined  limits, 
there  have  been  sunk  numerous  failures,  and  not  a 
single  productive  well.  All  those  failures  on 
the  southwestern  or  deep  side,  however,  may  be 
considered  as  being  of  insufficient  depth,  while 
the  northeastern  side,  representing  the  outcrop 
of  the  oil  horizon — as  the  writer  pointed  out 
several  years  ago—is  defined  permanently,  and 
nothing  of  any  consequence  can  be  expected  there. 
CL  This  clean-cut  limit  of  the  oil  field  may  be 

fifty-four 


ISOGEOTHERM  HYPOTHESIS 


accounted  for  on  the  supposition  that  the  separ- 
ate oil  strata  have  little  persistence  or  continu- 
ance of  porosity,  so  that  the  oil  has  always  re- 
mained well  in  its  defined  limits  of  original  de- 
position, and  indeed  this  seems  to  be  the  case,  as 
seldom  can  any  single  stratum  he  identified  with 
any  certainty  in  adjoining  wells. 
C,  The  old  time  driller  in  the  Whittier  field 
does  not  speak  of  "the  oil  sand  because  he 
knows  that  there  is  no  such  thing  as  a  definite 
oil  sand  there,  but  there  are  dozens,  perhaps 
hundreds  of  them,  so  many  that  it  is  impossible 
to  more  than  give  their  mode  of  occurrence. 
Perhaps  the  oil  in  some  of  these  separate  strata 
is  intercommunicable,  although  they  seem  to  be 
separated  by  well  defined  strata  of  impervious 
stale. 

CL  The  strata  in  this  field  dip  all  the  way  from 
45  degrees  in  the  southeastern  ends  to  vertically  in 
the  northwestern  end.  This  is  determined  by 
observing  the  dip  of  the  exposed  strata  at  the 
surface,  by  comparing  in  neighboring  wells  the 
depth  at  which  is  encountered  certain  persistent 
strata  that  may  reasonably  be  supposed  to  be 
continuous  from  well  to  well;  and  by  recovering 

fifty-five 


ISOGEOTHERM  HYPOTHESIS 


numerous  pieces  of  under-r  earnings,  containing 
portions  of  the  face  of  the  hole,  in  which  the 
bedding  is  plainly  marked. 


•V.v. 


The  northwest  end  of  the  ^X^hittier-Puente  oil  field.  Dots 
represent  -wells  that  are,  or  have  been  producers.  Outside  of  the 
area  represented  by  the  dots  no  profitable  wells  have  been  found. 
In  this  area,  practically  no  failures  have  been  obtained.  Most  of 
the  wells  are  many  years  old.  Development  has  been  going  on 
for  about  15  years.  Observe  that  the  direction  of  the  develop- 
ment, (•which  parallels  the  outcrop  of  the  oil  horizon)  is  N .\V.  and 
S.  E.,  although  the  steep-dipping,  outcropping  strata,  trend  east 
and  west:  showing  a  non-conformity  of  the  oil  horizon  to  the 
plane  of  stratification  of  nearly  45  degrees. 

CL  The  general  trend  of  the  kills  or  anti-cline 
conforms  closely  to  the  trend  of  the  oil  field,  so 
that  the  trend  of  the  strata  cuts  obliquely  across 


ISOGEOTHERM  HYPOTHESIS 


both.  It  has  often  been  held  by  persons  who 
nave  not  themselves  investigated,  that  this  is  im- 
possible; that  the  strike  of  the  strata  must  neces- 
sarily conform  to  the  axis  of  the  anti-cline,  but 
this  need  not  follow,  as  in  this  case  there  might 
have  been,  and  probably  was,  over  the  whole  re- 
gion originally,  a  universal  dip  of  the  strata  to 
the  south  southeast  before  the  anti-clme  began 
to  form. 

CL  This  feature  of  unconformity  of  the  outcrop 
of  the  oil  horizon  to  the  horizontal  trend  of  the 
strata  is  not  at  all  exceptional,  but  nowhere  else, 
perhaps,  does  it  occur  in  such  exaggerated  form. 
If,  however,  we  view  in  perspective,  a  profile 
of  the  oil  horizon  of  this  field  as  it  extends  into 
the  earth  in  the  direction  of  the  dip  of  the  strata, 
we  find  that  the  same  phenomenon  of  unconform- 
ity to  the  plane  of  bedding  occurs,  the  oil  hori- 
zon, as  in  most  other  fields,  dipping  roughly  about 
half  as  much  as  the  strata  does,  but  as  the  strata 
in  this  field  dips  very  steeply,  and  in  most  other 
fields  but  slightly,  the  unconformity  here  is  very 
noticeable,  while  in  other  fields  it  has  not  been 
sufficiently  noticed  to  cause  comment. 
CL  Here  we  have  under  consideration  an  oil 

fifty-»ev«n 


ISOGEOTHERM  HYPOTHESIS 


field  where  the  strata  stands  at  suck  a  pitch  that 
it  is  considerably  nearer  vertical  than  horizontal 
throughout  the  field;  the  field  extending,  not 
with  the  strata,  but  obliquely  across  it;  a  nar- 
row belt  or  oil  producing  territory  with  shallow 
wells  and  oil  outcroppings  on  one  side,  denoting 
the  outcropping  of  the  oil  horizon,  with  gradual- 
ly deepening  wells  towards  the  other  side  where 
the  field  is  defined  by  the  limitation  of  depth, 
the  cost  and  time  of  drilling  the  deep  wells  being 
heretofore  prohibitive. 

d,  I*  must  be  admitted  that  this  is  a  very  diffi- 
cult mafter  to  describe  comprehensively  to  those 
who  have  heretofore  not  given  it  much  a#ention, 
and  people  generally  have  somehow  got  the  no- 
tion that  oil  is  a  concomitant  of  certain  individ- 
ual strata,  and  must  necessarily  occur  in  connec- 
tion with  those  strata  and  nowhere  else,  and  it 
must  be  confessed  that  it  does  appear  so  in  an  oil 
country  like,  for  instance,  western  Pennsylvania, 
where,  sometimes  over  an  extent  of  twenty  or 
thirty  miles  the  oil  is  confined  to  one  or  two 
well  defined  strata,  which  can  be  unmistakably 
identified  for  that  distance;  however,  if  the  ob- 
server will  view  in  perspective  100  or  200  miles 

fifty-eight 


ISOGEOTHERM  HYPOTHESIS 


of  that  country,  lie  must  note  that  the  oil-con- 
taining horizon  as  a  whole  Joes  not  conform  to 
the  plane  of  stratification. 

d^  Now  what  Joes  this  orJerly,  I  will  not  say 
regular,  non-conformity  of  the  oil  horizon  to  the 
plane  of  stratification  signify?  Just  this,  it  gives 
us  the  key  to  the  origin  of  the  oil,  to  its  Jistilla- 
tion  from  helow  hy  the  heat  in  the  earth,  anJ 
its  final  Jeposition  in  its  original  isogeotherm,  or 
plane  of  equal  heat,  which  woul J  rarely  or  never 
he  in  exact  conformity  with  the  plane  of  strati- 
fication, anJ  as  the  region  slowly  emerge  J  from 
the  hot  Jepths,  anJ  the  miles  of  strata  ahove  he- 
came  worn  away,  the  strata  contmueJ  its  tilting, 
usually  on  the  same  orJer  it  hegan,  until  the  oil 
horizon  itself  hecame  contorteJ  anJ  Jippmg, 
though  usually  not  so  greatly  as  the  strata. 
C,  The  oil  at  Wli#ier  all  occurs  in  the  regular 
Puente  series  of  formation,  composeJ  of  shales, 
sanJs,  anJ  conglomerates.  Beginning  generally 
at  the  base  of  the  hills,  anJ  extenJing  south,  is  a 
much  later  formation,  resting  unconformahly  up- 
on the  Puente.  At  the  Leffingwell  ranch  this 
newer  Jeposit  extenJs  into  the  hills  in  a  hoJy  of 
several  hunJreJ  acres,  with  the  bo#om  of  the 

fifty-nine 


ISOGEOTHERM  HYPOTHESIS 


canyons  cu#mg  through  in  places  into  the  Puente 
series,  which  is  noticeably  different,  even  to  a 
novice.  At  several  other  places  there  are  de- 
tached patches  of  the  later  formation,  which  have 
so  far  escaped  complete  denudation. 
^  This  ma$er  of  more  than  one  series  of  de- 
posits, however,  is  of  liftle  interest  or  value  to 
the  oil  man,  for  the  lines  of  demarkation  mapped 
out  by  geologists,  separating  the  supposed  serial 
deposits  with  their  fanciful  names,  (generally  bor- 
rowed from  far  away  Britain),  is  no  barrier 
whatever  to  the  orderly  course  of  the  petroleum, 
and  coal  and  perhaps  other  horizons,  which, 
scorning  such  insignificant  obstacles,  keep  right 
on  into  and  through  many  named  deposits.  Even 
truly  separate  series  resting  unconformably  up- 
on each  other,  providing  they  had  reached  suf- 
ficient subsidence,  exert  no  influence  whatever 
upon  the  orderly  course  of  those  horizons. 
C^  The  continuation  of  the  ^!Vhi#ier  field,  or 
rather  the  outcrop,  is  in  an  E.  S.  E.  direction, 
along  the  Puente  hills,  and,  while  the  whole  oil 
horizon  does  not  outcrop — portions  continuing 
over  the  summit  where  the  hills  are  lowest — it 
outcrops  sufficiently  completely,  to  form  a  line  of 


sixty 


ISOGEOTHERM  HYPOTHESIS 


seepages  to  beyond  Olinda,  about  fifteen  miles. 
d^  This  outcropping  represents  the  edge  or  an 
immense  oil  field  which  has  Heretofore  teen  con- 
sidered too  deep  to  successfully  operate  to  any 
great  extent,  except  near  the  outcrop,  which  is 
somewhat  irregular,  owing  to  its  non-conformity 
with  the  steeply  dipping  outcropping  strata. 
These  strata  as  at  \Vhi$ier,  trend  east  and  west 
the  whole  distance,  while  the  line  of  seepages 
along  with  the  groups  of  wells  at  ^Vhi$ier, 
run  S.  E.;  a  few  miles  S.  E.  of  that  point, 
bend  more  easterly,  and  continue  about  E.  S.  E. 
to  Olinda,  being  considerably  out  of  conformity 
with  the  bedding  the  whole  distance. 
^  Recent  development,  in  closing  up  the  gaps 
between  the  groups  of  producing  wells,  has  a 
tendency  to  show  that  what  was  apparently  a 
succession  of  overlapping  oil  strata  a  thousand  or 
so  feet  apart,  with  barren  strata  between,  is 
really  a  practically  continuous  outcrop  of  the 
whole  oil  horizon,  altho  somewhat  irregular,  ow- 
ing no  doubt  to  the  irregularity  of  porous  strata, 
in  which  only,  the  oil  can  occur,  and  which  is 
absent  at  points  along  this  grand  outcrop. 
C  At  other  oil  fields  in  California  there  are 


sifcty-cm 


ISOGEOTHERM  HYPOTHESIS 


somewhat  like  conditions,  the  oil  horizon  rising 
ahruptly  from  a  great  depth,  and  outcropping  in 
steeply  dipping  strata,  the  porosity  of  the  oil 
sands  not  being  very  continuous  or  persistent,  so 
that  altho  some  of  the  minor  oil  deposits  have 
been  destroyed  by  surface  water  having  entered 
them,  the  near-by  deposits  are  uninjured. 
C.  A  remarkable  feature  of  this  Whi#ier-Pu- 
ente  oil  field  is  the  great  diversity  in  the  char- 
acter of  the  oil:  especially  in  the  gravity,  which 
ranges  from  a  tarry  fubstance  too  heavy  to 
pump,  up  to  36  gravity  (Baume.)  It  used  to  be 
thought  that  the  basic  oil  was  very  light,  and 
that  the  heavier  oils  had  become  so  through  the 
loss  of  their  volatile  constituents,  but  since  the 
field  is  better  developed,  it  appears  that  the  light- 
est oils  are  the  lowest  in  the  oil  horizon,  and  as 
a  rule  the  heaviest  are  highest  in  that  horizon. 
It  seemed  difficult  at  first  to  formulate  such  a 
rule,  because,  where  the  oil  horizon  cut  diagon- 
ally across  the  edge  of  the  steeply  upturned 
strata,  the  differing  oils  seemed  to  be  sandwiched 
in  the  oil  horizon  in  a  bewildering  manner,  but 
it  is  now  plain  that  those  deposits  that  are  con- 
fined to  the  N.  E.  side,  or  underside  of  the  oil 


ISOGEOTHERM  HYPOTHESIS 


horizon,  are  always  much  lighter  and  more  val- 
uahle  than  the  more  persistent  deposits  that  cut 
clear  across  the  oil  horizon,  and  the  very  tarry 
oil  is  confined  to  the  top  of  the  oil  containing 
horizon.  In  fact,  in  nearly  every  well  in  Cali- 
fornia, traces,  or  small  showings  of  tar  are  en- 
countered, usually  many  hundreds  of  feet  above 
the  main  bodies  of  oil,  and  operators  generally 
have  learned  to  pay  no  aftention  to  such  showings, 
as  they  are  usually  of  no  great  extent.  The 
very  light  oil  deposits  also,  are  generally  of  limit- 
ed extent,  and  the  wells  rarely  hold  up  as  well  as 
those  of  medium  gravity.  It  must  not  he  as- 
sumed, however,  that  because  a  strata  yields  a 
very  heavy  oil,  that  deeper  drilling  will  neces- 
sarily develop  a  deposit  of  light  oil  immediately 
under,  although  the  chances  are  such  as  to  be 
well  worth  the  cost  of  making  an  extra  thousand 
feet  of  hole,  -where  there  is  a  considerable  area 
to  be  proven.  In  other  California  oil  fields  it 
is  also  recognized  that  light  oils  are  most 
likely  to  be  found  lower  than  the  heavier 
oils,  but  the  practise  of  classifying  each 
level  at  which  oil  is  found,  as  a  separate 
oil  "horizon,"  has  confused  the  mafter. 

•ixty-three 


ISOGEOTHERM  HYPOTHESIS 


CL  People  who  object  to  the  subsidence,  or  iso- 
geotherm  hypothesis  of  petroleum  origin,  refer 
to  the  enormous  amount  of  deposit  it  would  ne- 
cessitate ahove  the  petroleum  zones  in  order 
to  secure  the  necessary  heat  to  properly  distill 
the  product  found  therein,  and  ask  for  proof  that 
there  were  two  or  three  miles  or  so  of  deposit 
ahove  it. 

CL  At  several  places  in  California,  notably  in  the 
Coyote  Hills  district,  it  is  more  than  4,000  feet 
to  the  oil,  and  the  only  reason  it  is  not  found 
deeper  at  other  places  is  ohviously  hecause  that 
is  close  to  the  practical  limit  that  can  he  reached 
without  an  outlay  or  cost  which  would  he  pro- 
hibitive. Indeed  it  is  only  the  last  few  years 
that  it  has  been  considered  practicable  to  go  more 
than  half  that  distance  in  California,  and  wells 
of  4000  feet,  cost  on  an  average,  at  least  thirty 
thousand  dollars. 

C,  The  strata,  where  it  is  cut  into,  4500  feet 
above  the  oil,  has  the  same  general  appearance 
and  texture,  as  it  has  in  the  oil  horizon,  or  be- 
low it.  The  inference  is,  that  if  there  had  not 
been  several  times  that  much  superincumbent  de- 
posit at  the  time  of  maximum  subsidence,  the 

eixty-four 


ISOGEOTHERM  HYPOTHESIS 


difference  in  texture  in  that  4500  feet  of  strata 
would  be  noticeable.  Then  the  temperature  at 
4000  feet  depth,  is  in  the  Coyote  field,  about 
170°  F.  which  would  amount  to  about  one 
degree  increase  for  40  feet.  The  deposit  is 
tertiary  and  the  universal  denudation  must  have 
been  very  great,  as  in  such  a  friable  formation, 
the  rate  of  elevation  would  hardly  much  exceed 
that  of  denudation. 

4L  But  what  is  especially  worthy  of  our  atten- 
tion is  the  enormous  amount  of  denudation  that 
would  occur  in  such  a  formation,  before  it 
emerged  above  the  surface  of  the  ocean.  Indeed 
it  never  would  have  so  emerged,  containing  the 
oil  horizon  intact,  had  it  not  been  protected  by 
immense  masses  of  coarse  flinty  sand,  the  sittings 
from  the  thousands  of  feet  of  denuded  superin- 
cumbent strata;  and  the  like  masses  of  similar 
sand  that  everywhere  protect  the  emerging 
beaches,  give  eloquent  testimony  to  this  univer- 
sal denudation  by  the  waves.  Nature  in  her 
destructive  operations,  takes  no  account  of  eco- 
nomic values, and  it  seems  that  recently  formed  oil 
strata  like  those  of  California,  that  have  not  had 
sufficient  age  to  harden  them,  are  as  often  as 

•ixty-firc 


ISOGEOTHERM  HYPOTHESIS 


not,  entirely  cut  to  pieces  by  the  wave  erosion 
in  their  emergence.  Examples  of  suck  oil  hori- 
zon erosion  can  be  witnessed  at  Point  Firmin, 
and  Summerland;  and  the  sbore  of  tbe  Pacific 
for  hundreds  of  miles  is  littered  witb  splasbes  of 
aspnaltum  and  paraf me,  that  come  from  the  erod- 
ed bottom. 


CANADA,  LAKEER:E.  WAPREN.TIDIUTE,  OILOTY, 


Diagram  showing  the  successive  occurrences  of  petroleum  and 
coal  across  western  Pennsylvania.  The  upper  series  of  short  line* 
represent  the  coal,  and  the  lower  ones  the  petroleum  horizons. 

4£  Millions  of  dollars  Lave  been  needlessly 
wasted  in  drilling  futile  exploration  wells  in  the 
last  60  years,  in  insistent  attempts  to  find  oil  in 
strata  that  were  supposed  to  correlate  with  strata 
tbat  are  oil  bearing  in  a  distant  locality,  but  which 
are  entirely  out  of  tbe  oil  containing  horizon. 

•ixt^-six 


ISOGEOTHERM  HYPOTHESIS 


Those  errors  are  made  mostly  where  the  oil 
fields  are  being  developed  in  the  direction  of  dip 
of  the  strata,  where  the  oil  horizon  generally 
passes  gradually  from  a  lower,  to  a  higher  strati- 
graphical  plane.  For  instance,  where  the  oil  is 
obtained  at,  say  1000  feet  depth,  and  it  is  known 
that  at  3000  feet  depth,  would  be  encountered 
strata,  that  correlated  with  oil  containing  stra- 
ta in  a  distant  locality.  Parties  frequently  sink 
wells  to  the  lower  level,  when  that  great  depth 
would  he  entirely  out  of  the  possible  oil  contain- 
ing horizon  for  that  locality.  This  has  been  go- 
ing on  ever  since  the  writer  was  a  boy,  and  he 
never  heard  of  an  instance  where  such  a  venture 
was  successful. 

^L  After  going  a  few  hundred  feet  below  the 
known  oil  containing  zone,  the  chance  of  en- 
countering oil  is  less  "with  every  foot  drilled,  re- 
gardless of  how  prolific  the  strata  are  elsewhere. 
CL  The  great  irregularity  of  the  occurrence  of 
petroleum  in  it's  horizons,  and  it's  tendency  to 
occur  in  extremely  prolific  deposits  on  or  near 
the  summits  of  anti-clmes,  may  be  accounted  for 
in  this  wise.  As  the  heated  strata  subsided,  and 
was  being  ""skimmed  of  its  volatilized,  carbon- 

eixty-»ev«n 


ISOGEOTHERM  HYPOTHESIS 


aceous  and  other  matter,  the  volatilized  mat- 
ter that  was  to  form  the  petroleum,  would  en- 
counter certain  strata  which  would  offer  more 
resistence  to  its  progress  upward  than  other  stra- 
ta, and  it  would  develop  a  tendency  to  follow 
lines  of  least  resistence  up  under  the  shelving 
strata,  thus  gathering  it  constantly  towards  the 
apex  of  the  anti-clines,  or  towards  a  region  of 
less  vertical  resistence. 

CL  There  are  cases,  on  the  edge  of  large  sedi- 
mentary areas,  where  quantities  of  oil  have  heen 
found  abutting  on,  and  over  granitic  masses.  In 
Placentas  Canyon,  near  Newhall,  California,  oil 
has  heen  found  in  small  quantities  where  the 
wells  were  started  in  granite.  Possihly  the 
granite  had  heen  elevated,  and  tilted  over  atop 
of  the  steeply  dipping  sedimentary  strata  which 
is  near  at  hand. 

^L  The  volatilized  matter  that  formed  coal, 
seemed  to  have  more  affinity  for  finegrained  im- 
pervious strata,  where  it  generally  finally  lodged, 
and  which  would  offer  little  resistance  to  its  up- 
ward movement,  consequently,  coal  is  found  to 
occur  much  more  evenly,  and  continuously  in  it's 
individual  deposits  or  teds. 


377446 


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